George evans



(No Model.) S

G. EVANS.

DENTAL TOOL. I No. 390,576; Patented Oct. 2, 1888'.

WITNESSES: wENTon l (A Z W1 Pff'w ATTORNEY N. PETERS, Phckv-Lkhagnphur.Wuhinglun. 0.0

NITED STATES PATENT Fries.

GEORGE EVANS, OF NEW YORK, N. Y.

DENTAL Toot.

SPECIFICATION forming part of Letters Patent No, 390,576. dated Qctober2, 1888.

I Application filed January 10, 1888. Serial No. 260.356. (No model.)

To a whom it may concern:

Be it known that 1, GEORGE EVANS, a citizen of the United States,residing at the city, county, and State of New York, have inventedcertain new and useful Improvements in Thermal Instruments forDentistry, of which the following is a specification.

The invention relates to instruments for con veyiug heat to narrowchannels or interstices of the teethas the nerve-canals in the rootsforthe purposes of drying the same preparatory to filling, or destroyinglive nerves by heat. Such instruments are commonly made of a bulb ormass of metal adapted as a reservoir to store heat derived from a tlameor other source, and to subsequently dispense the heat through a wire orprobe extending from the bulb,whereby the application is made at pointsdifficult of access.

The object of the present invention is to employ materials in theconstruction of this class of instruments such as will best and mosteffectually carry out their functions; and it consists in combining withthe bulb or reser' voir part, consisting of any suitable heat-retainingmetal-such as copper-a probe or point composed of silver, which,possessing greater thermal conductibility than other metals, I find inpractice to materially increase 0 the efficiency of the instrument.

Referring to the drawings accompanying this specification, Figure 1 is aperspective view of the instrument inserted to the nerve canal of atooth; and Fig. 2, an enlarged side view of the instrument, showing thebulb in section.

The bulb A, preferably of copper, is removably secured, as by ascrew-threaded stud, a, to the separate holder B, preferably of amaterial which will not conduct heat to the hand of the operator. Thelower end of the bulb A is provided with a screw-thread to receive thethreaded shank of the silver probe 0, which is readily removablethereby, and may be easily substituted for different ones, or in eventof injury. The silver, being ductile, admits, furthermore, of repeatedbending to accommodate the position of the cavity to be reached.

I claim- A dental heatapplyiug instrument composed ofa bulb-reservoir(as ofcopper) adapted for receiving and storing heat, and a probe ofsilver attached to and extending from said bulb, adapted to conduct thestored heat to a point of application.

GEORGE EVANS.

Witnesses:

CHAS. W. FORBES, S. P. VAN OAMPEN, Jr.

